According to Mary Turnipseed of Duke University’s Marine Laboratory, Woodie Guthrie got it wrong in 1940. What’s ours—as citizens and coastal residents–stretches well beyond “California and New York Island.” Two hundred miles out to sea, in fact.

And her point has everything to do with how to protect the ocean’s biodiversity.

Mary and her colleagues have argued that states–as well as the federal government–have a public trust to look after the oceans and the species that live there. Since 1983 that jurisdiction stretches 200 miles from shore.

That’s not only a lot of ocean. In total, it’s more surface area than our nation’s land area.

The Public Trust Doctrine is an American law that exists in all 50 states. Each state has its own version. [See this California version of the Public Trust Doctrine, for example.]

The state governments have to manage natural resources for the benefits of their citizens.

Commercial fishers (top) and recreational fishers (bottom) exploit marine biodiversity with catch restrictions that often do not maintain healthy populations of marine life. The Public Trust Doctrine argues that citizen interest requires state and federal governments to act in the broad interests of the public to manage marine resources.

Photos by Stuart L. Pimm

When the U.S. extended its authority out to the edge of its Exclusive Economic Zone—or EEZ–that added a band of jursidiction 200 miles around the coastline. And 200 miles around every island–however small, so long as that didn’t conflict with any other nation’s claim. There are lot of small islands scattered around the Pacific!

What bothers Mary is the government has not exercised its full public trust responsibilities to that space. “This fundamental law was never applied out that far,” she said.

“And what does that mean,” I asked.

“I think it’s hampered the ability of U.S. citizens to engage in the management of these resources–living and non-living,” she said.

Watch my interview with Mary in this video:

Video by Stuart L. Pimm

The ocean’s biodiversity is in bad shape. The reason that Mary and I were at the AAAS meeting was to brainstorm with many others about what one could do about it.

For whatever reasons, ocean life has been depleted of one species after another.

This gives me a chance to recommend a compelling book by Callum Roberts, of the University of York, in the UK. In The Unnatural History of the Sea, Callum tells of relentless destruction of marine resources over centuries. Callum has a deep fascination for history and is a great story teller.

Bluefin tuna is the poster child for a fishery where the agreed-upon limits always far exceed what scientists recommend–and everyone accepts that a lot of extra fish are landed illegally.

One solution that is growing in importance both in the U.S. and internationally are marine protected areas. “National Parks,” but in the oceans, not just on land.

An example is the Papahānaumokuākea Marine National Monument signed into existence by President Bush on June 15, 2006. It covers an area of 360,000 square kilometers (140,000 square miles) in the northwestern Hawaiian islands. It’s one of the largest marine protected areas in the world.

President Bush signs the proclamation to establish the Northwestern Hawaiian Islands Marine National Monument–later renamed the Papahānaumokuākea Marine National Monument. Marine Conservation Biology Institute Board Member Sylvia Earle (on the right) was present at the ceremony. Sylvia Earle is also a National Geographic Explorer-in-Residence.

Photo courtesy of Marine Conservation Biology Institute

The idea behind the Public Trust Doctrine, Mary told me, is that the fish–and all the other components of the ocean’s biodiversity–belong to all of us.

“For so long, we thought the seas were boundless–and we’ve managed them with that perspective, under that conceptual map. We just couldn’t have had that great an impact on our oceans. In fact, when we formed the EEZ it was to expand our fisheries–and to kick out the foreign fleets.

“Now we realized we’re having dire impacts. There are extreme depletions in large predatory fish. We’re looking for practical, tractable ways to improve ocean governance.”

With her colleagues, Mary published a paper in the journal Science last year. “The doctrine is a simple but powerful legal concept that obliges state governments to maintain natural resources in the best interests of their citizens,” she said.

That’s your ocean, my ocean–and everyone else’s. That it’s not just those for fish for sport or profit is bound to be very controversial.

Professor Stuart L. Pimm is a conservation biologist at Duke University, North Carolina. A former member of the National Geographic Committee for Research and Exploration, Pimm is the author of dozens of books and research papers, including the book “The World According to Pimm: A Scientist Audits the Earth.”

Post a comment

National Geographic Voices

Researchers, conservationists, and others share stories, insights and ideas about Our Changing Planet, Wildlife & Wild Spaces, and The Human Journey. More than 50,000 comments have been added to 10,000 posts. Explore the list alongside to dive deeper into some of the most popular categories of the National Geographic Society's conversation platform Voices.

Opinions are those of the blogger and/or the blogger's organization, and not necessarily those of the National Geographic Society. Posters of blogs and comments are required to observe National Geographic's community rules and other terms of service.

Voices director: David Braun (dbraun@ngs.org)

Fighting Wildlife Crime: The Unsung Heroes

Journalist and National Geographic Fellow Bryan Christy uses investigative journalism to expose illegal wildlife trafficking around the globe. In this video he introduces a a series of interviews with the people fighting wildlife crime on the front lines.

Blog Search

Search for:

Fulbright-National Geographic

The Fulbright-National Geographic Digital Storytelling Fellowship provides a unique platform for U.S. Fulbright awardees to build awareness of transnational challenges, comparing and contrasting cross-border issues. Their stories are shared on National Geographic digital platforms using a variety of digital storytelling tools, including text, photography, video, audio, graphic illustrations and/or social media. Meet the Fellows and follow their adventures across the world on the Fulbright-National Geographic Storytelling blog.

Follow the links on the sidebar of any of the blog's pages for details and tips on how to apply for a Fellowship.